From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D5F62C432C3 for ; Fri, 22 Nov 2019 15:53:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B78822071B for ; Fri, 22 Nov 2019 15:53:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726887AbfKVPx6 (ORCPT ); Fri, 22 Nov 2019 10:53:58 -0500 Received: from gentwo.org ([3.19.106.255]:39220 "EHLO gentwo.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726546AbfKVPx6 (ORCPT ); Fri, 22 Nov 2019 10:53:58 -0500 Received: by gentwo.org (Postfix, from userid 1002) id 5EDB93F3D6; Fri, 22 Nov 2019 15:53:57 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by gentwo.org (Postfix) with ESMTP id 5DE683EBFD; Fri, 22 Nov 2019 15:53:57 +0000 (UTC) Date: Fri, 22 Nov 2019 15:53:57 +0000 (UTC) From: Christopher Lameter X-X-Sender: cl@www.lameter.com To: Pengfei Li cc: David Hildenbrand , akpm@linux-foundation.org, mgorman@techsingularity.net, mhocko@kernel.org, vbabka@suse.cz, iamjoonsoo.kim@lge.com, guro@fb.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC v1 00/19] Modify zonelist to nodelist v1 In-Reply-To: <20191122234907.4da3bc81.fly@kernel.page> Message-ID: References: <20191121151811.49742-1-fly@kernel.page> <1bb37491-72a7-feaa-722d-a5825813a409@redhat.com> <20191122234907.4da3bc81.fly@kernel.page> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 22 Nov 2019, Pengfei Li wrote: > I am sorry that I did not make it clear. I want to express this series > of patches will benefit NUMA systems with multiple nodes. Ok but that benefit needs to be quantified somehow. > The main benefit is that it will be more efficient when traversing all > nodes (for example when performing page reclamation). And you loose the prioritization of allocations through these different zones. We create zonelists with a certain sequence of the zones in order to prefer allocations from certain zones. This is in particular important for the smaller DMA zones which may be easily exhausted.